Table 4.
Analysis of Prognostic Factors for Loco-regional Recurrence-free Survival
| Variables | 3-year loco-regional recurrence-free survival (%) | P-value | |
|---|---|---|---|
| Univariate | Multivariate | ||
| RT technique | |||
| IMRT vs. 3D-CRT | 82.4 vs. 73.5 | 0.714 | 0.415 |
| Age (years) | |||
| <50 vs. ≥50 | 66.0 vs. 93.8 | 0.077 | 0.053 |
| Gender | |||
| Male vs. female | 82.2 vs. 71.4 | 0.546 | |
| Smoking status | |||
| Current or previous vs. never | 80.5 vs. 77.8 | 0.879 | |
| Alcohol status | |||
| Current or previous vs. never | 72.8 vs. 100 | 0.138 | 0.421 |
| WHO histologya | |||
| 1 vs. 2-3 | 66.7 vs. 87.4 | 0.120 | 0.478 |
| T stage | |||
| 1-2 vs. 3-4 | 85.7 vs. 75.5 | 0.353 | 0.273 |
| N stage | |||
| 0-1 vs. 2-3 | 87.5 vs. 76.8 | 0.650 | |
| AJCC stage | |||
| 3 vs. 4 | 85.2 vs. 68.6 | 0.186 | 0.181 |
| GTV (cc) | |||
| ≤55 vs. >55 | 91.7 vs. 70.9 | 0.134 | 0.377 |
| Total dose (BED, Gy10) | |||
| ≤82.5 vs. >82.5 | 60.4 vs. 100 | 0.010 | 0.201 |
| Daily dose (Gy) | |||
| ≤2 vs. >2 | 86.1 vs. 61.0 | 0.167 | 0.094 |
| RT duration (weeks) | |||
| ≤7.5 vs. >7.5 | 85.9 vs. 73.3 | 0.385 | 0.576 |
| RT interruption | |||
| Yes vs. no | 81.8 vs. 78.7 | 0.917 | |
| Induction chemotherapy | |||
| Yes vs. no | 78.3 vs. 80.1 | 0.878 | |
RT, radiotherapy; IMRT, intensity-modulated radiotherapy; 3D-CRT, 3-dimensional conformal radiotherapy; WHO, World Health Organization; AJCC, American Joint Committee on Cancer Staging; GTV, gross tumor volume; BED, biologically equivalent dose.
a
WHO histology I, keratinizing squamous cell carcinoma; II, non-keratinizing carcinoma, differentiated type;III, non-keratinizing carcinoma, undifferentiated type